Fuel supply control system for internal combustion engines

Abstract

A fuel supply control system for an internal combustion engine calculates a basic amount of fuel to be supplied to the engine, based on the rotational speed of the engine and load on the engine. An amount of fuel adhering to the inner wall surface of the intake passage of the engine is estimated to calculate an adherent fuel-dependent correction amount. An amount of fuel carried off from the inner wall surface of the intake passage into at least one combustion chamber of the engine is estimated to calculate a carried-off fuel-dependent correction amount. The basic amount of fuel is corrected such that the air-fuel ratio of a mixture supplied to the engine becomes equal to a desired air-fuel ratio determined depending on operating conditions of the engine to obtain a corrected basic fuel amount, and at the same time the corrected basic fuel amount is corrected by the use of the adherent fuel-dependent correction amount and the carried-off fuel-dependent correction amount to calculate an amount of fuel to be supplied to the engine. At least one of the adherent fuel-dependent correction amount and the carried-off fuel-dependent correction amount is corrected according to the desired air-fuel ratio.